#include <cstdio>

int main() {
    char str[101];

    fgets(str, 101, stdin);

    int cnt = 0;
    for (int i = 0; str[i]; i++) {
        if (str[i] >= '0' && str[i] <= '9') {
            cnt++;
        }
    }
    printf("%d\n", cnt);

    return 0;
}
